Questionif i'm 90% effaced and starting to dialate does that mean I've already lost my mucos plug? And how long before my water will break ?
AnswerNature may already have answered these questions for you, but just in case, here goes. :-)
When you lose your mucous plug, you will almost certainly know it. The exception might be if it happens when you go to the restroom and most of it falls into the toilet--but even then you will probably feel it or see it. The mucous plug is a large amount of mucous, sometimes streaked slightly with blood or simultaneous with some light bloody show. Losing it is a sign that your body is preparing for labor, but you can lose your mucous plug quite a long time before active labor begins--in some cases, two weeks beforehand! Don't be disappointed if you lose your plug and then don't go into immediate labor. Take it instead as an encouraging sign that your body is doing just what it should to prepare for the birth.
The bag of waters, or amniotic sac, can break anytime from 24 hours before you go into active labor until right after the baby is born. Occasionally it happens even sooner before active labor, but many healthcare providers get concerned about infection if the onset of labor takes too long after the water breaks, and so they recommend inducing labor (using means such as pitocin) if 24 hours or more have passed since the waters have broken and labor has not begun. If the baby gets all the way through the labor and birth with the bag of waters intact, this is known as being born in a caul. Many cultures consider this a sign of a blessed birth; it is an unusual occurence, however. :-) There is no standard of when the waters will break.
I hope these answers were helpful to you. Please let me know if you have any other questions, and good luck on your upcoming birth. :-)